Generator rotors have a cylindrical rotor body from which two shafts extend at each rotor end. The rotor is angularly divided into teeth regions and pole regions. The teeth regions have a series of teeth that are defined by longitudinal slots cut into the rotor. The slots contain field windings and wedges for holding the windings in place against centrifugal force caused by the rotor rotation.
Co-pending U.S. patent application Ser. No. 08/819,433, filed Mar. 17, 1997 (Assignee Docket No. P96-002), which is assigned to the assignee of the present invention and is incorporated herein by reference in its entirety, describes such a generator rotor.
Thermal expansion of the windings, as well as other forces, often cause stress-induced cracking of the rotor. A long retaining ring attachment modification to repair such cracks is often part of a reconditioning program after prolonged rotor use. Such a modification requires replacing the retaining ring, often requires rewinding of the rotor, and requires significant down-time. U.S. Pat. No. 5,528,097 to Gardner et al., which is assigned to the assignee of the present invention and incorporated herein by reference in its entirety, describes modifications to a rotor/retaining ring system.
There is a need for a method of repairing rotor stress cracking that diminishes the downtime and cost associated with the long retaining ring modification.